This link leads to the machine-readable files that are made available in response to the federal Transparency in Coverage Rule and includes negotiated service rates and out-of-network allowed amounts between health plans and healthcare providers. The machine-readable files are formatted to allow researchers, regulators, and application developers to more easily access and analyze data. https://www.uhc.com/united-for-reform/health-reform-provisions/transparency-in-coverage-rule
Machine Readable Files can be found here.